Method of finishing wood



Patented Sept. 4, 1934 METHOD OF FINISHING WOOD Frank Tuchfarber, deceased, late of Cincinnati,.

Ohio, by William' K. Divers, administrator, Cincinnati, Ohio, assignor, by mesne assignments, to R. W. Callaway, New York, N. Y. and Alan N. Mann, Scarsdale, N. Y., as joint trustees No Drawing.

v'7 Claims.

The invention herein involved relates to a new method of treating wood, or other material having fibrous surfaces, as part of the finishing op-* eration. This treatment is particularly aimed to producing surfaces of great beauty but in addition when applied (particularly in preferred form) to wooden members used as sounding boards in musical instruments as, for example, violins or the sounding boards of pianos, it produces an ex-. traordinarily fine resonance. It is recognized that natural wood when dry has a better resonance than the same wood finished in ordinary ways, but a finish is necessary to preserve the wood and prevent undue penetration of moisture. Finishes applied using the invention of this application preserve the resonance and tone quality to a marked degree. a

In its prefe-rredembodiment, the invention is a very simple one and consists in formulating a combined solution and suspension of gluten and gamboge in water, which is applied to the clean, smooth surface of the natural wood and allowed to dry. The wood should preferably be in the white and not previously treated. This first application results in the formation on the surface of the wood of a muddy unattractive layer which completely or substantially hides the surface .of the material. This, however, is followed with coatings of usual commercial varnish, or lacquer, or other like film-forming material made with an organic solvent: Immediately after the first coating of this finishing material'is put on, a distinct change in the surface is observed, and within a few moments there is obtained a beautiful luminous eifect giving. richness and clearness to each detail of the grain markings. Apparently this result is due to the fact that the preliminary treatment coats the surface of the wood with a.

layer of minute particles of substantially colloidal '40 size, and these are gradually dissolved in the subsequent layers of finish. Where gamboge is employed, the color seems to blend through into each successive layer of finishing material, making a highly refractive film which seems to bring 4 out, through selective action, all the beauty of the grain markings, emphasizing the character of each species of wood. As might be expected, the.

effect is particularly beautiful on light, highly grained woods such as maple and birch, 'yet its efiect on such woods as mahogany and walnut is strikingly noticeable.

Apparently the preliminary treatment is such that there is very little penetration, for the solid material tends to'stay on the surface and acts to prevent the subsequent penetration of the Application December 13, 1932, 'Serial No. 646,998

finish even thoughthis solid material is dissolved in the finishing coat. According to observations made when the coating is applied, the protective qualities of the finishon wood are probably a function of the adhesion developed between the fibers of the wood and the-protective film. Under the layer of solid particles formed according to the present invention, the preliminary coating described forms a continuous resistant film which, as the gradual solution of the particles takes place, becomes an integral part of the subsequent coats,so that the several layers are welded into a protective body which is very effective as a moisture retardant andlikewise assists in holding the film mass in the desired semi-fluid state essential to a permanent, durable finish. Because of this action this treatment is in some cases valuable as a base for pigmented film forming materials, as for example in the case of coating very porous bodiesfsuch as pressed board made of vegetable fibers.

'Asjstated above, the preferred embodiment of the invention utilizes gluten and gamboge. Gamboge is a gum resin with a part soluble in water and a resinous part which is insoluble. The gum which is dissolved in water seems to serve as a dispersing agent to assist in' maintaining the insoluble resin in suspension. The gluten also appears to act as a dispersing agent, smoothing the product and making it easier to apply and it may act somewhat to plug the pores of the wood and prevent undue penetration. It will readily be seen that numerous materials can be used as more or less equivalent to the preferred ingredients; for example, myrrh is a gum resin having qualities somewhat similar to gam- Y boge but without including the characteristic yellow color, and myrrh gives quite similar results to gamboge. Also synthetic gum resins can readily be produced by grinding with water in a colloid mill a natural resin such as rosin, or a synthetic resin such as a phenolic resin while in the intermediate or so-called soluble state, with a gum such as gum arabic or tragacanth. In like manner, there are various recognized equivalents for gluten which will serve as dispersing agents, such for example as casein, various vegetable proteins or soaps, and in some cases the gum raising of the grain or swelling of the surface fibers, especially when the coating is applied with the grain with rapid, even strokes, or preferably by spraying. A particularly notable characteristic of the composition is its rapid drying, making it possible to apply the first coat of finish within an hour after the preliminary treatment. The usual time is allowed to lapse between subsequent applications of the finish, and the surface may or may not be rubbed down between coats, according to the type of finish desired. However, it will be found that fewer coats of the finishing material are needed than is ordinarily the case.

The method in which the preliminary treating material is prepared can readily be understood from thefollowlng example, though this is given only by way of example and the proportions used may be modified widely:

A medium sized teaspodniul of gluten fiour is placed in a cup. To this is added a teaspoonful of clean water. The two are stirred together into a smooth paste and there is then added an ounce or two of lukewarm water which is likewise stirred in. The thinpaste thus formed is then added to about two gallons oi lukewarm water and slowly boiled until the volume is reduced to one gallon. i

If these direcfions are followed, it will insure a thorough cooking of the gluten, but it is to be understood that they are not positive limitations.

The gallon of material thus prepared is cooled and filtered through a coarse filtering medium and care should be taken to preserve this solution against souring.

One and one-half ounces of powdered gamboge are mixed with six ounces of clean water andthoroughly agitated. After allowing the two to stand together for about 24 hours, preferably with frequent agitation, the material is filtered through a coarse filter, such as a linen or muslin cloth, which will remove. suspended particles of excessive size; but this filtering step may not be necessary if the gamboge has been reduced to a sufliciently fine powder in the first instance.

To make the complete preliminary coating material, the gluten water and gamboge suspension may be mixed in equal volumes. These proportions are intended only as a guide to the practiceof the invention and are subject to wide variation; for example, the materials may be mixed in pro;- portions ranging up to 3:1, with either of the ma-. terials forming the greater proportion. As stated above, under some circumstances thegluten may be entirely omitted, but ordinarily its presence improves the result. The complete coating material improves if allowed to stand for a number of hours before using.

The preliminary coating material is preferably applied quite rapidly over the surface of the clean, smooth wood, A brush may be used or a small pad, such for example, as may be made by wrapin the PM of. finishing wood.

The invention herein described when applied to wood and other-fibrous surfaces according to the usual methods of one familiar with the art of finishing, results in the formation of finished surfaces of superior quality as regards both beauty and utility with marked economy in both time and cost'of application. Further, as has already been stated, when this finish is usedin connection with musical instruments it produces musical sounding boards rich and mellow.in ,tone with resonant carrying qualities, presumably because the film of the coating layers is held on the surface, permitting the wood to retain its natural vibratory characteristics.

What is claimed is:

l. The method of finishing fibrous surfaces which comprises applying to such a surface a colloidal suspension in water of an undissolved resinous material insoluble in water but soluble in organic solvents, permitting the resulting coating to dry without substantially softening the resinous ingredient, and applying a film forming compound comprising an organic solvent adapted .to dissolve said resin.

I 2, The method of finishing fibrous surfaces which comprises applying to such a surface a watery suspension comprising an undissolved resinous material insoluble in water but soluble in organic solvents, andran'organic dispersing agent, permitting the resulting coating to dry without substantially softening the resinous ingredient and applying-a film-forming material comprising an organicsolvent adapted to dissolve said resin. 3. The method of finishing fibrous surfaces which comprises applying to such a surface a watery suspension comprising an undissolved resinous material insoluble in water, a water-soluble gum and an organic dispersing agent, permitting the resulting coating to dry without substantially softening the resinous ingredient and applying a film-forming material comprising an organic solvent adapted to dissolve said resinous material.-

4. The method of finishing fibrous surfaces which comprises applying to such a surface a watery suspension of an undissolved gum resin and an organic dispersing agent, permitting the forming material comprising an organic solvent adapted todissolve said resin.

5. The method of finishing fibrous surfaces which comprises applying'to such a surface a watery suspension of gamboge and gluten, permitting the resulting coating to dry, and applying a film-forming material comprising an organic solvent adapted to dissolve the non-water soluble portions of the gamboge.

- 6. As a new article of manufacture, a fibrous board-likebody having a protective film firmly adhering to the surface thereof without. extensive penetration, such film resulting from the solution in situ of a layer of distinct particles of substantially colloidal size of asoluble resin by an ingredient of a finishing film-forming material applied thereto. v

'7. As a new article of manufacture, a wooden sounding board having a protective film firmly adhering to the surface thereof without extensive penetration, such film resulting from the solution in situ by an ingredient of a film forming material applied thereto, of a layer of distinct particles of substantially colloidal size of a resin soluble in organic solvents but insoluble in water which is present on the surface of such board in conjunction with an organic dispersing material.

K. DIVERS, Administrator el- Erank T hjarber; Deceased. 

